Medical fluid cassettes and related systems and methods

• US 9,694,125 B2
• Filed: 12/16/2011
• Issued: 07/04/2017
• Est. Priority Date: 12/20/2010
• Status: Active Grant

• Current Assignee: Fresenius Medical Care Holdings Incorporated (Fresenius Medical Care AG)
• Original Assignee: Fresenius Medical Care Holdings Incorporated (Fresenius Medical Care AG)
• Inventors: Plahey, Kulwinder S., Ohline, Robert Matthew, Ortega, Anthony Thomas, Farrell, Sean
• Primary Examiner(s): Stigell, Theodore
• Assistant Examiner(s): Koo, Benjamin
• Application Number:
  US13/994,286
• Publication Number:
  US 20140018728A1
• Time in Patent Office: 2,027 Days
• Field of Search: 604151
• CPC Class Codes: A61M 1/1522 the interface being evacuated interfaces to enhance contact
• CPC Class Codes: A61M 1/1524 the interface providing means for actuating on functional elements of the cassette, e.g. plungers
• CPC Class Codes: A61M 1/155 with treatment-fluid pumping means or components thereof
• CPC Class Codes: A61M 1/1561 at least one cassette surface or portion thereof being flexible, e.g. the cassette having a rigid base portion with preformed channels and being covered with a foil
• CPC Class Codes: A61M 1/159 specially adapted for peritoneal dialysis
• CPC Class Codes: A61M 1/16 with membranes
• CPC Class Codes: A61M 1/28 Peritoneal dialysis ; Other peritoneal treatment, e.g. oxygenation
• CPC Class Codes: A61M 2205/12 with interchangeable cassettes forming partially or totally the fluid circuit
• CPC Class Codes: A61M 2205/121 interface between cassette and base
• CPC Class Codes: F04B 43/02 having plate-like flexible members, e.g. diaphragms F04B43/14 takes precedence

Abstract

A medical fluid pumping system that includes a medical fluid pumping machine that includes an actuator and a medical fluid cassette that can be disposed within a cassette enclosure of the medical fluid pumping machine. A member is disposed within a fluid pump chamber of the medical fluid cassette and is magnetically attracted to the actuator such that the member and the actuator can be coupled together when the cassette is disposed within the cassette enclosure.

Claims

1. A medical fluid pumping system, comprising:

a medical fluid pumping machine defining a cassette enclosure, the medical fluid pumping machine comprising an actuator configured to reciprocate; and

a medical fluid cassette configured to be disposed within the cassette enclosure of the medical fluid pumping machine, the medical fluid cassette comprising

a base;

a membrane attached to the base, the membrane cooperating with a region of the base to define a fluid pump chamber and covering an entire area of the fluid pump chamber, the cassette positionable within the cassette enclosure of the medical fluid pumping machine so that the actuator is substantially aligned with the fluid pump chamber; and

a member disposed within the fluid pump chamber, the member including a magnetically attractive material to couple the member to the actuator with a portion of the membrane positioned between the actuator and the member when the cassette is disposed within the cassette enclosure,

wherein the member and the actuator are configured to be reciprocated together relative to the base when the member is coupled to the actuator.

2. The medical fluid pumping system of claim 1, wherein the member is shaped to substantially conform to a recess in the region of the base that cooperates with the membrane to form the fluid pump chamber.

3. The medical fluid pumping system of claim 2, wherein the member and the recess in the region of the base that cooperates with the membrane to form the fluid pump chamber are substantially dome-shaped.

4. The medical fluid pumping system of claim 1, wherein the actuator comprises one or more magnets, and the member comprises a magnetic material that is attracted to the magnets.

5. The medical fluid pumping system of claim 4, wherein the member comprises a magnetic plate that is secured to a non-magnetic material.

6. The medical fluid pumping system of claim 5, wherein the magnetic plate is surrounded by the non-magnetic material.

7. The medical fluid pumping system of claim 1, wherein the actuator comprises a magnet plate that defines a plurality of recesses and a plurality of magnets disposed in the recesses.

8. The medical fluid pumping system of claim 7, wherein the magnets are arranged in the recesses such that at least some adjacent magnets have opposite polarities.

9. The medical fluid pumping system of claim 8, wherein at least some of the magnets are arranged in a circular pattern, and all circumferentially adjacent magnets within the circular pattern have opposite polarities.

10. The medical fluid pumping system of claim 7, wherein the actuator further comprises a cover plate that can be secured to the magnet plate that defines the recesses to retain the magnets within the recesses.

11. The medical fluid pumping system of claim 1, wherein the member has a substantially flat surface that abuts a substantially flat surface of the actuator.

12. The medical fluid pumping system of claim 1, wherein the member is attached to the membrane of the cassette.

13. The medical fluid pumping system of claim 1, wherein the member comprises a first portion and a plurality of resilient legs extending from the first portion.

14. The medical fluid pumping system of claim 13, wherein the base defines channels configured to receive the legs to hold the member in a desired position within the chamber.

15. The medical fluid pumping system of claim 13, wherein the first portion is substantially dome-shaped.

16. The medical fluid pumping system of claim 1, wherein the actuator can be retracted a sufficient distance away from the base of the cassette to decouple the actuator from the member.

17. The medical fluid pumping system of claim 16, wherein the medical fluid pumping machine comprises a post that is arranged to be received in a bore at least partially formed by the actuator as the actuator is retracted, and the post can prevent movement of the member in a direction of the retracting actuator to facilitate decoupling of the actuator from the member.

18. The medical fluid pumping system of claim 1, wherein the medical fluid pumping machine comprises first and second actuators, and the membrane and regions of the base cooperate to define first and second fluid pump chambers, the cassette is positionable within the cassette enclosure of the medical fluid pumping machine so that the first and second actuators substantially align with the first and second fluid pump chambers, and first and second members are disposed within the first and second fluid pump chambers, respectively, the members being magnetically attracted to the actuators when the cassette is disposed within the cassette enclosure.

19. The medical fluid pumping system of claim 1, further comprising a cover that releasably attaches to the cassette, the cover comprising a projection that holds the member in contact with or in near contact with the base of the cassette when the cover is attached to the cassette.

20. The medical fluid pumping system of claim 1, wherein the medical fluid pumping system is a dialysis system.